3D Printing Supports: Overhanging Features in a Design

3D printing Supports are tools meant to hold cantilevered section of
meshes. Their shape depends on the material and technology used.

A part with 3D printing supports generated using meshmixer

Material Support

In this case, a part is printed on a bed dense enough so that cantilevered
section do not fall as they are printed. Material support needs
to be more dense than the printed part. This is mostly the case
of jet modeling and
SLS. In case of jet modeling two types of resins are used, one for
the part and another specifically for the material support. In
the case of
SLS it is the unsintered powder that acts as material support preventing
parts to fall, this is not possible in the case of metal printing
as the sintered part is too dense and would "sink" in the metal
powder.

Printed Support

In the case where there is no structure to hold the part, which is
common case, with FDM and
SLA, supports must be added to the part in order to make it self sustaining,
The image shows the area where they are needed in order to print
the part. Those supports will be printed along with the part. The
connection to the model must be made as thin as possible in order
to allow removal. In the case of metal printing removing the supporting
structure will require machining tools.

Analysing a part using meshmixer to find cantilevered section

Batch fabrication

In the case of
SLS printing the absence of added supporting structure allows the manufacturer
to optimize his batches. The fabrication process therefore includes
a nesting phase where models are clustered together. The goal is
to reduce the printing volume, which will result in a faster
printing and less wasted powder. Heuristic algorithms are used
to find optimal spatial arrangement of meshes. This optimization
ultimately allows Sculpteo to offer more competitive prices which
the reasoning behind the batch control tool.